TY - JOUR

T1 - Forest Age Rivals Climate to Explain Reproductive Allocation Patterns in Forest Ecosystems Globally

AU - Ward, Rachel E.

AU - Zhang‐Zheng, Huanyuan

AU - Abernethy, Kate

AU - Adu‐Bredu, Stephen

AU - Arroyo, Luzmilla

AU - Bailey, Andrew

AU - Barlow, Jos

AU - Berenguer, Erika

AU - Chesini‐Rossi, Liana

AU - Cho, Percival

AU - Dahlsjö, Cecilia A. L.

AU - das Neves, Eder Carvalho

AU - de Oliveira Sales, Bianca

AU - Farfan‐Rios, William

AU - Ferreira, Joice Nunes

AU - Freitag, Renata

AU - Girardin, Cécile

AU - Huaraca Huasco, Walter

AU - Joly, Carlos A.

AU - Malhi, Yadvinder

AU - Marimon, Beatriz

AU - Marimon Junior, Ben Hur

AU - Morel, Alexandra C.

AU - Muller‐Landau, Helene C.

AU - Peixoto, Karine da Silva

AU - Reis, Simone

AU - Riutta, Terhi

AU - Salinas, Norma

AU - Seixas, Marina

AU - Silman, Miles R.

AU - Kueppers, Lara M.

PY - 2025/8/25

Y1 - 2025/8/25

N2 - Forest allocation of net primary productivity (NPP) to reproduction (carbon required for flowers, fruits, and seeds) is poorly quantified globally, despite its critical role in forest regeneration and a well‐supported trade‐off with allocation to growth. Here, we present the first global synthesis of a biometric proxy for forest reproductive allocation (RA) across environmental and stand age gradients from a compiled dataset of 824 observations across 393 sites. We find that ecosystem‐scale RA increases ~60% from boreal to tropical forests. Climate shows important non‐linear relationships with RA, but is not the sole predictor. Forest age effects are comparable to climate in magnitude (MAT: ß = 0.24, p = 0.021; old growth forest: ß = 0.22, p < 0.001), while metrics of soil fertility show small but significant relationships with RA (soil pH: ß = 0.07, p = 0.001; soil N: ß = −0.07, p = 0.001). These results provide strong evidence that ecosystem‐scale RA is mediated by climate, forest age, and soil conditions, and is not a globally fixed fraction of positive NPP as assumed by most vegetation and ecosystem models. Our dataset and findings can be used by modellers to improve predictions of forest regeneration and carbon cycling.

AB - Forest allocation of net primary productivity (NPP) to reproduction (carbon required for flowers, fruits, and seeds) is poorly quantified globally, despite its critical role in forest regeneration and a well‐supported trade‐off with allocation to growth. Here, we present the first global synthesis of a biometric proxy for forest reproductive allocation (RA) across environmental and stand age gradients from a compiled dataset of 824 observations across 393 sites. We find that ecosystem‐scale RA increases ~60% from boreal to tropical forests. Climate shows important non‐linear relationships with RA, but is not the sole predictor. Forest age effects are comparable to climate in magnitude (MAT: ß = 0.24, p = 0.021; old growth forest: ß = 0.22, p < 0.001), while metrics of soil fertility show small but significant relationships with RA (soil pH: ß = 0.07, p = 0.001; soil N: ß = −0.07, p = 0.001). These results provide strong evidence that ecosystem‐scale RA is mediated by climate, forest age, and soil conditions, and is not a globally fixed fraction of positive NPP as assumed by most vegetation and ecosystem models. Our dataset and findings can be used by modellers to improve predictions of forest regeneration and carbon cycling.

KW - forest ecosystems

KW - climate

KW - forest age

KW - ecosystem modelling

KW - soil fertility

KW - reproductive allocation

KW - forest regeneration

U2 - 10.1111/ele.70191

DO - 10.1111/ele.70191

M3 - Review article

VL - 28

JO - Ecology Letters

JF - Ecology Letters

SN - 1461-023X

IS - 8

M1 - e70191

ER -